假单胞菌WX14群体感应淬灭酶基因的克隆及其功能研究  

Isolation and Characterization of Quorum-quenching Genes from Bacterium Pseudomonas sp.WX14

作　　者：张清霞[1] 张迎 吉艳艳 童蕴慧[1] 纪兆林[1] ZHANG Qmgxia;ZHANG Ying;JI Yanyan;TONG Yunhui;JI Zhaolin(College of Horticulture and Plant Protection, Yangzhou University, Yangzhou 225009, Chin)

机构地区：[1]扬州大学园艺与植物保护学院,扬州225009

出　　处：《中国生物防治学报》2018年第1期109-116,共8页Chinese Journal of Biological Control

基　　金：国家自然科学基金(31772210);江苏省重点研发计划(现代农业)重点项目(BE2017344;BE2015354)

摘　　要：本研究采用报告菌平板法及β-半乳糖苷酶活性测定并筛选到10株具有较强降解酰基高丝氨酸内酯(AHLs)能力的细菌,其中菌株WX14降解AHLs能力较强,且菌体和菌体外泌物均具有降解活性。利用PCR法从菌株WX14中克隆到hac A和hac B两个群体感应淬灭酶基因,基因全长分别为2286和2370 bp,氨基酸序列比对分析结果表明,Hac A属于阿库来菌素A酰化酶蛋白家族,Hac B属于青霉素G酰化酶蛋白家族。这两个基因编码产物均为N末端亲核(N-terminal nucleophile,Ntn)水解酶家族成员。将hac A和hac B导入到软腐果胶杆菌Pectobacterium carotovorum后,可减弱该细菌在马铃薯块和白菜上的致病性,因此这2种AHLs降解酶对依赖于群体感应的软腐病有一定防病作用。经16S rDNA序列同源性分析鉴定,3株为假节杆菌Pseudarthrobacter spp.、1株节杆菌Paenarthrobacter sp.、4株假单胞菌Pseudomonas和2株芽胞杆菌Bacillus spp.。In this study,ten strains w ith strong AHLs-degr ading activity were obtained through ―reporter plate‖ and the assay of β-galactos idase activity.Strain WX14 displayed the highest AHLs-degrading activity and the AHLs-degrading capac ity was observed in bacter ial cells and extracellular secretions.Quorum quenching genes hac A and hac B were identif ied and cloned from strain WX14,and full lengths of these two genes are 2286 bp and 2370 bp,respectively.Analys is of amino sequence s imilar ities showed that Hac A belongs to aculeac in A acylase family,and Hac B belongs to penic illin G acylase f amily.Both Hac A and Hac B ar e members of the N-terminal nucleophile hydrolase superf amily.It was observed that Pectobacterium carot ovorum Z3-3 after introduced hac A or hac B attenuated its pathogenic ity in potato tubers and Chinese cabbages,indicating thes e two AHLs degrading enzymes might have potential to control of the QS-dependent soft rot disease.BLAST n analys is of bacter ial 16 S rDNA sequences showed that ten isolates were identif ied as Pseudarthrobacter spp.（3 isolates）,Paenart hrobacter sp.（1 isolate）,Pseudomonas spp.（4 isolates） and Bacillus spp.（2 isolates）,respectively.

关 键 词：群体感应淬灭 酰基高丝氨酸内酯 酰基转移酶 N末端亲核水解酶 

分 类 号：S476[农业科学—农业昆虫与害虫防治]